RandyOo writes: I've recently learned that our neighborhood is getting a fiber optic network, with a 100Mbps connection in each subscriber's home. IPv6 connectivity is included, but unfortunately, the only IPv4 connectivity they offer is Carrier Grade NAT (CGN), due to the exhaustion of IPv4 addresses in RIPE.

I travel a lot, and I've become accustomed to accessing my home network via SSH, VNC, etc. It appears uPNP and PMP are unsupported by CGN. So, without a publicly-routed IPv4 address, I'll be unable to reach devices on my home network from an IPv4-only connection, such as the one provided by my cellular carrier. (which also appears to be behind some kind of NAT, by the way)

If the ISP isn't willing or able to sell me an IPv4 address, what alternatives do I have? I'd be willing to pay a small monthly fee for, say, a VPN service that would allow me to accept incoming connection requests on a range of ports on their internet-facing IPv4 address. Does such a service exist?

LogMeIn has a product called "Hamachi" that will give you a personal VPN. You can use it to access devices behind a CGN device. If you need support on mobile devices where the Hamachi client is unavailable, you can rent a small VPS server at a host somewhere, install Hamachi on it, and use it to "bounce" ssh and other ports into your Hamachi VPN.

Chances are you'll need to pay the ~$30 yearly fee for using Hamachi to bypass the "free" restrictions (it only works if there's a user logged in on Windows and Mac